IP Library › Granted Patent US 10,645,687

Granted Patent B2

US 10,645,687 · App. 15/905,567 · Granted May 5, 2020

Method for transmitting HE-LTF sequence and apparatus

Inventors: Xin Xue (Shenzhen, CN); Ningjuan Wang (Shenzhen, CN); Le Liu (Shenzhen, CN); Wei Lin (Shenzhen, CN)

Assignee: HUAWEI TECHNOLOGIES CO., LTD.

H04W72/044 H04L5/0048 H04L27/262 H04L27/2613 H04W84/12

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Quick Facts

Patent No.: US 10,645,687
App. No.: 15/905,567
Granted: May 5, 2020
Kind: B2

External Links

USPTO Patent Center↗ Full Patent PDF↗

Abstract

Embodiments of the present invention provide several long training sequences that are in a wireless local area network and that comply with 802.11ax.

Claims (13381)

1. A method for sending a long training sequence in a wireless local area network, the method comprising:

obtaining, by an apparatus, according to a transmission bandwidth, an HE-LTF sequence corresponding to the transmission bandwidth; and

according to a size and a location of a resource block (RU) allocated to a station, mapping a sequence segment in the HE-LTF sequence to subcarriers in the allocated RU wherein the sequence segement's location correpsonds to the location of the allocated RU, and

sending the sequence segment;

wherein a 4× HE-LTF sequence in an 80 MHz bandwidth transmission is HE-LTF 4x (−500:500), the HE-LTF 4x (−500:400)comprises values on subcarriers with indexes −500:500,

⁢

LTF

⁡

(

500

⁢

500

)

[

⁢

]

2. The method according to claim 1 , wherein:

the HE-LTF sequence is a stored sequence or a generated sequence;

the generated HE-LTF sequence is constructed by

HELTF

⁢

⁡

(

500

⁢

500

)

{

⁡

(

)

⁡

(

)

⁢

}

where G e ={1,−1,1,−1,1,1,1,1,−1,−1,−1,1,1,1,1,1,1,1,1,−1,1,−1,−1,1,1,−1},

Ga=[+1 +1 +1 +1 +1 +1 −1 +1 +1 +1 −1 +1 +1 −1 −1 −1 +1 −1 +1 −1 −1 +1 +1 −1 +1 −1]; and

Gb=[+1 +1 +1 +1 −1 −1 +1 +1 +1 +1 +1 −1 +1 +1 −1 −1 −1 +1 −1 −1 −1 +1 −1 +1 −1 +1],

G a p is obtained after a phase of a value at a pilot location of the Ga sequence is reversed,

G b p is obtained after a phase of a value at a pilot location of the Gb sequence is reversed;

G c is obtained after a phase of a value on an even-numbered subcarrier of the Ga sequence is reversed;

G d is obtained after a phase of a value on an even-numbered subcarrier of the Gb sequence is reversed;

G c p is obtained after a phase of a value at a pilot location of a G c sequence is reversed, and

G d p is obtained after a phase of a value at a pilot location of a G d sequence is reversed.

3. A method for receiving a data packet in a wireless local area network, comprising:

receiving a data packet, by an apparatus;

obtaining, by the apparatus, according to a transmission bandwidth of the data packet, an HE-LTF sequence corresponding to the transmission bandwidth; and

determining, by the apparatus, according to a size and a location of a resource block (RU) allocated to a station in the data packet, a corresponding HE-LTF sequence segment as a reference sequence that corresponds to the RU for channel estimation;

wherein a 4× HE-LTF sequence in an 80 MHz bandwidth transmission is HE-LTF 4x (−500:500) comprises values on subcarriers with indexes −500:500,

⁢

LTF

⁢

⁡

(

500

⁢

500

)

[

]

4. The method according to claim 3 , wherein:

the HE-LTF sequence is a stored sequence or a generated sequence;

the generated HE-LTF sequence is constructed by

HELTF

⁢

⁡

(

500

⁢

500

)

{

⁡

(

)

⁡

(

)

⁢

}

where G e =1,−1,1,−1,1,1,1,1,−1,−1,−1,1,1,1,1,1,1,1,1,−1,1,−1,−1,1,1,−1,

Ga=[+1 +1 +1 +1 +1 +1 −1 +1 +1 +1 −1 +1 +1 −1 −1 −1 +1 −1 +1 −1 −1 +1 +1 −1 +1 −1]; and

Gb=[r+1 +1 +1 +1 −1 −1 +1 +1 +1 +1 +1 −1 +1 +1 −1 −1 −1 +1 −1 −1 −1 +1 −1 +1 −1 +1]

G a p is obtained after a phase of a value at a pilot location of the Ga sequence is reversed,

G b p is obtained after a phase of a value at a pilot location of the Gb sequence is reversed;

G c is obtained after a phase of a value on an even-numbered subcarrier of the Ga sequence is reversed;

G d is obtained after a phase of a value on an even-numbered subcarrier of the Gb sequence is reversed;

G c p is obtained after a phase of a value at a pilot location of a G c sequence is reversed, and

G d p is obtained after a phase of a value at a pilot location of a G d sequence is reversed.

5. An apparatus applied in a wireless local area network, comprising a processor and a memory, wherein the memory stores instructions for the processor to:

obtain, according to a transmission bandwidth, an HE-LTF sequence corresponding to the transmission bandwidth;

according to a size and a location of a resource block RU allocated to a station, map a sequence segment in the HE-LTF sequence to subcarriers in the allocated RU, wherein the sequence segment's location corresponds to the location of the allocated and

send the sequence segment;

wherein a 4× HE-LTF sequence in an 80 MHz bandwidth transmission is HE-LTF 4x (−500:500), the HE-LTF 4x (−500:500) comprises values on subcarriers with indexes −500:500,

⁢

LTF

⁢

⁡

(

500

⁢

500

)

[

]

6. The apparatus according to claim 5 , wherein:

the HE-LTF sequence is a stored sequence or a generated sequence;

the generated HE-LTF sequence is constructed by

HELTF

⁢

⁡

(

500

⁢

500

)

{

⁡

(

)

⁡

(

)

⁢

}

where G e ={1,−1,1,−1,1,1,1,1,−1,−1,−1,1,1,1,1,1,1,1,1,−1,1,−1,−1,1,1,−1}